Fat aspiration can only achieve body contouring, but not weight loss or even weight reduction. For example, familial obesity is very difficult to treat and requires long-term diet control and physical exercise to burn off the accumulated fat in the body, in addition to some whole-body tests to rule out endocrine or other causes of obesity. Liposuction can only extract part of the subcutaneous fat out of the body, but cannot “eliminate” all the fat inside and outside the whole body. For people who are obese all over the body, besides the subcutaneous fat, a large amount of fat will accumulate in the deep layer of the trunk and the abdominal cavity, which cannot be removed by liposuction.